Update 2: Brewers Association spokeswoman Barbara Fusco says the organization had alerted its members that registration would sell out fast, but they weren't sure exactly how fast.

"Everything is going gangbusters in craft brewing right now, and registering for the festival is no exception. Last year, it was just under two days. This year, it was just under two hours," she says. "We always encourage breweries to sign up for the waiting list, though, because there is always some level of attrition every year."

She said that registration problems that some breweries may have had online were likely the result of one of the association's servers experiencing difficulties.

Although registration is closed, the association doesn't yet know exactly how many breweries will end up pouring in the hall this year, she adds. There will probably be more than 600 in attendance, however, up from a revised total of 578 last year.

Update 1: Brewery registration for the Great American Beer Festival has now sold out, meaning that breweries that didn't get it done this morning will have to sign up for the waiting list.

Registration opened today for breweries who want to be part of the Great American Beer Festival, which returns to Denver on October 10-12, but because registration sold out in just two days last year, beer makers are scurrying to submit their information.

As a result, the website for the Boulder-based Brewers Association, the national trade group that hosts GABF every year in Denver, was overloaded this morning. A few breweries around the country are expressing frustration via social media about the web site problems, but the BA is encouraging them to be patient and try again.

Several breweries were shut out last year despite that fact that GABF organizers upped the number of breweries to 580 in 2012, a whopping 23 percent increase over the previous year and the highest number of breweries ever included at the festival.

The number is expected to rise even higher in 2013.

Brewers Association spokesman Barbara Fusco couldn't immediately be reached about the web site problems or the GABF brewery cap, but she said in an earlier email to Westword that, "Yes, to reflect the growth in the number of breweries around the country, we are once again looking to make some floor plan changes that will allow us to accommodate additional participating breweries."

So far, several Colorado brewers have told followers on Twitter and Facebook that they have picked their beers or registered successfully. They include Trinity, Hogshead, Caution, Vertboten, Front Range Brewing, Echo, Arvada Beer, Lone Tree Brewing, Pateros Creek, Brewery Rickoli and Strange Brewing.

Tickets to attend GABF will go on sale to the general public on July 31.